1. Field of the Invention
One or more embodiments of the present invention generally relate to a carbon nanotube based interposer for use in device related to board interconnect technologies.
2. Background Art
An interposer (or socket) is generally defined as an interface that is sandwiched between an electrical device, a substrate, and conductive material (or pads) on a printed circuit board (PCB). The electrical device is a die or silicon. The electrical device may be, but not limited to, an integrated circuit (IC) packaged in the form of a surface mount device (SMD). The electrical device is supported by the substrate. The substrate interfaces with the electrical device to spread the electrical connection of the electrical device to a wider pitch. The interposer generally includes a support structure that is positioned below the substrate. The support structure is supported by the PCB. The substrate and the support structure each generally include electrically conductive interconnects positioned therein. The electrical device transfers electrical signals to the PCB via interconnects within the substrate and the support structure.
In general, the electrical interface between the substrate and the support structure may include solder balls/columns or direct attach pins. Such an electrical interface that comprises solder balls/columns or direct attach pins are generally limited to smaller interposer packages. Above a certain size threshold (e.g., such thresholds may vary based on different substrate and PCB materials), larger interposers may be needed. Functionality and reliability of the larger size interposers may not be achievable due to dissimilar properties between the substrate/electrical device (or package) and the PCB. Such dissimilar properties may result in different expansions at operating conditions as well as shape changes (i.e., flexing) that may lead to failure.
For high power electrical devices, power delivery is limited by heating and voltage drops across the conductive interconnects in the interposer. In many cases, to enable power delivery for high power devices, a large number of interconnects are needed. Such an increase in the number of interconnects leads to a larger package and may further complicate the thermally-driven mechanical mismatch problem noted above.